A song in 1970 by Eric Burdon and War, it is known as the hippy anthem. It means shooting up heroin as the wine spilling is blood and the pearl is heroin heating up on a spoon.
Person A: Hey man! Do you wanna go Spill The Wine and Grab That Pearl with us out in that field?
Person B: Sure man, if its good shit!
Person A: Only the purest nigga!